Reply to comment

I can't say that I completely believe in the theory geological differences determined the differences in culture. I would rather buy the concept of the gene decides the cultural evolution. The concept of culture in my mind was always what people think, how people behave and the values of a society. It just seems superfluous to give a geological reason to the diversity of cultures.

    What we would like to believe is in our blood. Can you give a reason to the religious believes? Is it also a geological difference? Then why do people in different countries share similar believes? The moslems don't eat pork, that's because they worship pigs. It is said during a war, pigs dig a hole so that the ancestors could escape and survive. Not eating pork had became a culture for moslem ever since. It was just a random incident which created a culture.  

    Look at half blood people. They often have personalities that are the mixtures of their parents. Asians are mostly conservative, Europeans and South Americans are more ebullient and adventruous. The offsprings of Asians with Europeans or South Americans are likely to have both of those qualities. The culture which the half bloods have is not simply Chinese, Japan, French or Mexican. Gene plays the main rule in the cultural mixture. 

    The determinant of cultures is not a simple factor. Maybe it's just randomness. People thousands of years ago just thought, behaved and believed in certain ways. Maybe it's just another turtle story. I'd rather count and track down the turtles than settle for a simple reason.